Field of the Invention
The present invention relates to a method for printing at least one section of a surface of an object, which includes carrying out a relative movement between an inkjet head and the object to move the inkjet head along a first path and print a first track in the process and to move the inkjet head along a second path and print a second track in the process. Furthermore, the present invention relates to a method for printing at least one section of a surface of an object, which includes moving an inkjet head along a first path and printing a first track in the process and moving the inkjet head along a second path and printing a second track in the process.
The invention lies in the technical area of inkjet printing, in particular the printing of substrates that are not flat but curved. “Curved” means that the surface has convex and/or concave sections, etc., such as body parts of vehicles.
The known prior art in this technical area includes the following:
German Patent Application DE 10 2012 006 371 A1, corresponding to U.S. Patent Application Publication No. 2015/0042716, has already disclosed a method and a device which permit the printing of curved surfaces and the drying of the print. In that case, an inkjet head and a dryer are guided along the object or vice versa by using a robot in the otherwise homogenous printed image. German Patent Applications DE 10 2013 016 006, corresponding to U.S. Patent Application Publication No. 2015/0085046 and DE 10 2014 004 507, corresponding to U.S. patent application Ser. No. 14/670,698, disclose methods and a device which, in particular, permit spherical objects to be printed, in which the respective object is moved.
German Patent Application DE 10 2013 014 444, corresponding to U.S. patent application Ser. No. 14/474,460, discloses a method which permits the planning of paths for the printing and drying of curved surfaces and the guidance of the print head/the dryer on the planned paths.
German Patent Application DE 10 2012 006 370 A1, corresponding to U.S. Pat. No. 8,882,242, and German Patent Application DE 10 2013 019 359, corresponding to U.S. patent application Ser. No. 14/547,365, disclose methods and devices which, during the printing of curved surfaces, permit the planning or execution of a plurality of parallel paths in such a way that perceivable defects in the lateral connection of the printed ink tracks are avoided.
If the print must be dried, it may be necessary to print short tracks, in order to be able to dry the same without any disruptive time delay. However, a multiplicity of short tracks also produces a multiplicity of connections of the tracks to one another. As a result, the probability of perceptible defects in the connection can also rise.
In addition, it is known that the human eye perceives long lines extending rectilinearly more easily than short ones extending in curves.